3D images of fluorescence tagged tissue samples are obtainable from confocal or non-confocal (thick slice) light microscopic studies. Due to the finite size of the fluorescence tags and that of the light source, the images are blurred and thus a de-blurring process is needed to restore the contrast and to improve the resolution of the images. De-blurring by deconvolution has been found to be useful in the case of non-confocal images. The 3D data processing, however, is tedious and requires knowledge of the point-spread-function (PSF) which may not be space-invariant. If we start from 2D confocal images, the situation will be simplified considerably. The PSF may be obtained, experimentally or theoretically, in a 2D sense and, likewise, subsequent deconvolutions performed in 2D. Presentation of 3D volumes is also important in revealing detailed structures. After processing the 2D slices, surface or volume rendering procedures are needed to present the object as a connected 3D volume. Mensuration of structural details is required on improved images. The confocal images we obtained were from the sonic muscles of the California Teleost fish swimbladder. Due to its extraordinary capability of stretching and expansion, the sonic muscle is in itself of interest in its Z-line structure and construction. (Z-line studies are also important in the research of Nemaline myopathy, a neurological disease.) The titin molecules in the muscle were tagged with various fluorescence dyes. 2D confocal slices obtained from the microscope were recorded and transferred to a personal computer where an IDL program was written for data re- formatting and rearrangement into a 3D stack. This stack was in turn used as input to a volume rendering program, 3DVIEWNIX (Udupa et al, Medical Image Processing Group, U. Penn.), for manipulation and visualization. At this stage, we have successfully tested data flow, manipulation, and visualization programs. We have been investigating several imaging packages, including NIHImage, IDL, ImageMagick, 3DVIEWNIX, and MIPAV (McAuliffe, CIT, NIH). Each has its own features, but none can do all that we need to do. Therefore, in-house code and a combination of these packages have been used. Major emphasis on deconvolution will be our next stage of work. The PSF has to be obtained from experiment. The Program package Voxel Blast will be evaluated. In-house programming may again be needed. - Confocal EM, Image Processing